1. Field of the Invention
The present invention relates to a digital image input/output apparatus or a digital copying machine with an image compressing/expanding means and an image storage means.
2. Description of the Related Art
In conventional digital copying machines, input original image information from a scanner is temporarily held in a page buffer. Whenever an original is input from the scanner, the image information is compressed, and the compressed image information of a plurality of originals is stored in a file buffer.
These conventional digital copying machines have a so-called electronic sort function by which the compressed image information stored in the file buffer is subjected to single-side or double-side printing in a sort mode or a group mode by appropriately changing the output order of the image information.
When a large quantity of originals are to be copied, for example, the file buffer sometimes becomes full while the originals are being input from the scanner. If this is the case, a series of original input operations are interrupted, and the copied products of originals that are input up to this point are output, thereby completing a single job.
If the number of originals is large, therefore, it is necessary to output the copied products before the remaining originals can be input, resulting in a cumbersome operation.
Also, a plurality of originals are joined and output in the form of a single copy in some instances such as in double-side printing. If the file buffer is filled up after an original for one side is input, the other side of a copy to be subjected to double-side printing remains blank. The result is that the copying operation cannot be well completed.